Objective: Present study designed to evaluate the effectiveness of an extract obtained from Cleome dolichostyla
on calcium oxalate crystallization in vitro. Materials and Methods: In this laboratory research, after taking the aqueous extract of 5 grams of Cleome dolichostyla
by 100 ml of distilled water at gentle heating, the formation and dissolution of calcium oxalate in the absence and presence of extract was investigated by complexometric and conductometric methods. Results: The effect of the extracts on the prevention of sediment formation was studied and the results of the conductometric titration curve method for leaves of Cleome dolichostylashowed a significant difference (175.0 µmol) between the concentration of calcuim in the absence (450.0 µmol) and presence of the extract (625.0 µmol) andfor seeds, the difference was (38/0µmol) in the absence (450/0µmol)andpresence (488/0 µmol)of the extract. In the study of the effect of extract on the stone dissolution, the results of the complexometry method showed that the amount of calcium measured by the dissolution of calcium oxalate crystals for the leaves of Cleome dolichostylain the presence of extract, was 2.5 µmolhigherthan that in the absence of extract and for seeds was 6.0 µmol higher. Conclusion: According to this study, Cleome dolichostyla
aqueous extract dissolves calcium oxalate kidney stone, but can not prevent the formation of them.